Field Investigation on the Window-Opening Behavior and Indoor Environment Performance in Naturally Ventilated Residential Building: A Case Study of Student Dormitory in ITB Jatinangor Campus

Window-opening behavior is one of the critical factors to ensure the effectiveness of natural ventilation in improving indoor air quality, thermal comfort, and energy-saving in buildings. This research aims to investigate the window-opening behavior and its effects on indoor thermal condition in a public apartment in Jatinangor, Indonesia. A questionnaire survey and field measurement were carried out to analyse the window-opening behavior and thermal environment, respectively. The result shows that most occupants prefer to open the balcony door than the window. Fresh air intake and heat removal were the main reasons for opening the window; on the other hand, the outdoor environment (e.g., dust and noise) was the reason for closing the window. This study also revealed that opening the window at night could lower indoor temperature up to 2.7 °C. Meanwhile, opening windows during the daytime may lead to excessive heating in indoor spaces. Furthermore, opening the window/door could elevate the indoor airspeed up to 0.5 m/s higher compared to the unit where all windows/doors are closed. This research provides insights into the window/door design for low-energy buildings.